External tools expand longevity of legacy solutions. Integrated tools can enable an existing application to provide new functionality. An existing solution lacking modern functionality can add modern features through integrated tools. However, most third party tool solutions are custom developed and lack flexibility. Most legacy applications rarely provide standardized interfaces to integrate external tools. Vendors develop custom solutions to integrate external tools for inflexible legacy applications at great cost to a customer. Custom solutions are rarely portable or upgradeable. In addition, a typical vendor developing external tools spends significant resources to maintain in house legacy knowledge base. Legacy knowledge bases depreciate at alarming speed with each new product cycle and change in the technology.
User authentication schemes rarely work well across external tools and legacy applications. A user seeking access to protected resources in a legacy application is usually forced to authenticate separately for the external tool and the legacy application. The user is forced to break flow of a work process and provide duplicate credentials through multiple log-in processes. In addition, privileges usually do not propagate from the legacy application to the external tool. External tools can be forced to implement expansive and exotic authentication schemes to gain privileges to access protected resources of the legacy application. Forcing the user to manage multiple credentials for a single task complicates user productivity.